1. Technical Field
The present invention relates to a semiconductor device, a manufacturing method thereof, and an electronic apparatus.
2. Related Art
For multilayer semiconductor devices, accurate positioning has been required to bond bumps. For this reason, bonding has been performed by applying heat and pressure using a flip chip bonder. However, there has been a problem that when using solder to bond bumps, the solder overflows from the bonding portions due to the application of heat and pressure and thus a bonding failure easily occurs.
In the configuration described in JP-A-2001-53218, an insulating film is formed on side surfaces of back surface terminals protruding from a silicon substrate. For this reason, at the time of bonding, excessive solder may extend to the vicinities of the terminals thereby becoming shorted to the silicon substrate. Also, there has been a problem that even if a non-weighting bonding method, such as reflow bonding, is used, the bonding strength decreases if the tips of back surface terminals are flat surfaces as in JP-A-2001-53218.
In order to solve this problem, there has been a proposed configuration where Cu of side surfaces of back surface terminals is exposed and a base portion on a silicon substrate is covered by an insulating film, as shown in JP-A-2004-297019. The Cu-exposed portions on the side surfaces of the terminals contribute to solder bonding. The formed solder takes a shape having a skirt extending from the vicinities of the back surface terminals to terminals on an active surface of the semiconductor substrate (silicon substrate). Thus, a short between overflow solder and the semiconductor substrate or a short between the terminals can be avoided. Since the bonding area is increased, the bonding strength is also increased.
However, even if the method described in JP-A-2004-297019 is used, the solder amount is difficult to control. Therefore, it is difficult to avoid a bonding failure completely. Also, the pitch has been narrowed to meet the downsizing demand. However, there remains a problem that the related-art structure uses solder bonding and therefore the pitch is difficult to narrow.